In the past, an elevator supervisory system for supervising and controlling elevators has separate supervisory or monitoring devices provided in accordance with objects to be monitored, respectively, so that the supervision of the elevators is carried out by elevator supervisory devices, and the monitoring of the interiors of elevator cars is carried out by car interior monitoring devices (see, for instance, a first patent document).    [First Patent Document] Japanese patent application laid-open No. 2000-351546